Usually, such camera-based systems are calibrated at the end of a production line during the vehicle manufacture by means of special test objects, wherein both an alignment of an area to be detected as well as an optimal color detection and a white balance are adjusted. In particular with such systems, which have a camera arranged in an interior of the vehicle and an imaging performed through a pane of the vehicle, when exchanging the pane, unless it is not replaced by a pane of the same type, a renewed calibration must be performed to avoid quality losses, since different pane types very strongly differ in their transmission properties. For this purpose, for the various types of the panes corresponding sets of parameter to be selected are stored in the system or the system is individually adapted to the new pane. This new calibration must be performed in a specialist garage.
From DE 10 2006 056 180 A1, which is incorporated by reference, a method and an apparatus for calibrating an image sensor in a vehicle is known. The calibration is made here depending on the properties of a vehicle pane. The apparatus comprises an image sensor for detecting the environment information, a computer unit, which evaluates detected environment information, as well as a selection means for selecting parameter settings of the image sensor. Within the method at least one marking on the vehicle pane is detected and evaluated by means of an image sensor. On the basis of the detected marking properties of the vehicle pane are determined. Thereby the parameters of the image sensor are set suitably for the detection of image information on the basis of the determined properties of the vehicle pane.
It is disadvantageous here that only vehicle panes can be used, which have a detectable and identifiable marking, which necessitates an additional production expenditure for the production of these vehicle panes. If vehicle panes are used, which do not have such a marking, there is no calibration, from which quality losses result in the detection of environment information. Moreover, in prior art methods it is required to first provide a vehicle pane with a marking, which contains information on the vehicle pane. It is further disadvantageous that with incorrect markings incorrect calibrations are performed.